Finned engine cylinder



Jan.7, 1941. DSLHERSEY 2,227,933-

FINNED ENGINE CYLINDER Filed April 25, 1939 a2 I /2 M ,4

24 U 28 i g I llllllnul I "U 1 H /6"f-L l I III II l I L I I 1 I vINVENTOR V I flDIJHHSZi-Z'I'SW smw -\TTORNEY Patented Jan. 1, 1941UNITED STATES PATENT OFFICE FINNED ENGINE CYLINDER. Donald S. Hersey,West Hartford, Conn assignor to United Aircraft Corporation, EastHartford, Conn, a corporation of Delaware I Application April 25, 1939,Serial No. 269,8'lll 1 Claim.

This invention relates to an improved construction for finned enginecylinders and has for an object the provision of improved means forproducing a composite engine cylinder.

A further object of the invention. resides in the provision of animproved cylinder construction having a steel barrelportion, sheet metalfins andan aluminum intake duct and valve mechanism supports. i

I A still further object resides in the provision of improved means forsecuring aluminum fins toya steel cylinder barrel and providing suitablesupports for the valves and valve operating mechanism.

5 Other objects and advantages will be more particularly pointed outhereinafter or will become apparent as the description proceeds.

In the accompanying drawing, in which like reference numerals are usedto designate similar parts throughout, there is illustrated an exampleof an improved cylinder constructed according to purpose of illustrationonly and is not to be taken as limiting or restricting the scope of theinvention. i

In the drawing, the single figure is a longitudinal sectional view of afinned engine cylinder constructed according to the invention, a portionof the cylinder barrel being shown in elevation.

0 Referring to the drawing in detail, the numeral j I 0 generallyindicates a cylinder barrel, preferably formed of steel of desiredphysical characterlstics. The cylinder is provided with a closed outerend in the form of a combustion chamber iiiv dome within which areprovided the valve ports and spark plug apertures, the intake valve portbeing indicated by the numeral l2, the exhaust port by the numeral lland a spark plug aperture by the numeral I6. Near its open end the .0cylinder barrel is provided with an external flange i8 by means of whichit maybe secured to an engine crankcase and has below the flange a skirtportion adapted to extend through the cylinder aperture in the crankcaseto assist in L5 maintaining the cylinder in position on the crankcaseand to bring a portion of the cylinder within the diameter of thecrankcase. Above the crankcase the cylinder barrel is provided withexternal beads as indicated at 22, 24 and 26 for a purpose 50 which willpresently appear.

Above the bead 22 the barrel is surrounded by a series of annular finsof varying diameter, as generally indicated at '28. These fins arepreferably made of sheet metal in order to provide is closely spacedheat radiating fins of great depth the invention. The drawing, however,is for the.

which are, at the same time, equally spaced an suificiently strong toresist the vibratory effect imposed on the cylinder by the engineoperation. The cylinder head and the exhaust port casing ina jig orfixture and the 'fins are assembled l5 about it and alternated withsplit spacing rings to provide the proper spaces between the individualfins. The jig preferably has an outer casing the interior of which bearsagainst the peripheries of the fins which are cut to the proper 20diameters so that as the fins are assembled about thebarrel which isheld in the jig the proper spacing will be maintained between the inneredges of the fins and the exterior'surface of the barrel.

Suitable molds are centered on the intake port l2 to provide the intakeconduit, intake valve. guide 14, and intake valve mechanism housing I6,and a mold is also centered on the combined exhaust conduit liner andvalve guide 38, which 30 is preferably made of steel and welded orotherwise secured to the barrel in before beginning assembly of the fin,to provide the exhaust valve mechanism housing 40.

After the fins and molds have been assembled about and upon the barrelIll within the forming Jig or external mold, molten aluminum is forcedunder high pressure into the spaces between'the cylinder barrel and thefins and fin spacers, and the spaces about the valve conduits and valve40 mechanism housing molds to provide a matrix of die cast aluminumbetween the barrel and the inner edges of the fins, and die cast valvehousings. As indicated by the line 42 the fin spacers terminate somewhatshort of the inner 45 edges of the fins to permit the cast metal tosurround the inner edges of the fins for an appreciable depth to providea good heat conducting bond between this metal and the fin the same timeit perfects the bond with the exterior surface of the cylinder barrel.

The head 22 may effectively cooperate with the exterior mold to limitthe downward extent of the fin securing casting, the intermediate bead24 extends .into the casting to increase the strength of the bondbetween the casting and the barrel in a direction longitudinally of thebarrel while the bead 26, besides reinforcing the barrel around theothers skilled in the art may clearly understand" the same, what it isdesired to secure by Letters Patent is as follows:

A composite engine. cylinder comprising, a steel barrel member having aclosed head end providing a combustion chamber, valve ports in said headend, a steel exhaust port liner and valve guide secured to the peripheryof the exhaust port in said head end, spaced sheet metal finssurrounding said barrel and overlying the head end thereof around saidports spaced from the outer surface of said barrel, and an aluminumcasting filling the space between the finned portion of the surface ofsaid barrel and said fins and including the inner edges of said fins toprovide a supporting and. heat conducting bond between said barrel andsaid flns,- said casting also surrounding said exhaust conduit liner andvalve guide and extending therebeyond to provide a valve mechanismsupport and extending outwardly from the intake port in said head toprovide an intake conduit and'valve guide and valve mechanism supportfor said cylinder.

DONALD S. HERSEY.

